JP2001014794A - Recording type optical disk and its recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording type optical disk disabling digital copy from a reproduction-only optical disk to recording type optical disk and its recording method. SOLUTION: This recording type optical disk is composed of a data area 1 where data are recorded, and a read-in area 2 including a control data block 3 consisting of two areas of a pre-pit recording area 5 where fixed data containing invalid scrambled key data 11 are permanently recorded in a non- erasable form and a recordable area 4, to disable recording of scrambled key information for releasing scrambling of the data, and errors enough to disable error correction are inserted in a part of an inner code pertaining to an area where the scramble key 11 does not exist in the pre-pit recording area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recordable optical disk which makes it impossible to digitally copy digital data from a read-only optical disk in which digital data is permanently recorded, that is, pre-pit recorded in advance, and a recording method for the recordable optical disk.

[0002]

2. Description of the Related Art Optical disks have the characteristic that they can be randomly accessed and stored for a long period of time, and have the characteristic that they can be copied in large quantities at low cost by mastering by the disk manufacturer. For this reason, for example, CDs have become popular as high-quality digital audio, replacing conventional analog recording records. In recent years, DVD-ROMs in which high-quality image data are digitally recorded
VIDEO is commercialized, and it is expected that optical disks as digital recording media for AV data will further develop in the future.

On the other hand, the above-mentioned CD and DVD-VIDEO
Not only read-only optical disks in which data is pre-recorded in the form of pre-pits by disk manufacturers, but also recordable optical disks that allow users to record AV data at home in recent years, such as CD-R and CD-RW , M
D, DVD-RAM, DVD-R, and DVD-RW have been developed, and optical disk devices capable of recording and reproducing both recording-type and read-only optical disks with one device are spreading.

However, as described above, if both a recording type and a read-only type optical disk can be handled by one apparatus, the copyright for the AV data recorded in the read-only type has become a major issue. In other words, a general user can illegally copy AV data recorded on a read-only optical disc onto a recordable optical disc as it is, without paying a copyright fee that should be paid to the creator of the AV data, and digital recording. This is because illegal copying can be obtained without deterioration of sound quality or image quality. This is becoming a factor that hinders the spread of high-quality content. As a measure against such illegal copying, for example, when copying from a CD to an MD, the sound quality is slightly degraded, or a recording device or a recording disk is shipped with an additional amount corresponding to the copyright in advance. Means have been used, but it is impossible to collect copyright in a perfect form, and there is an essential problem in that digital copying from a read-only optical disk to a recordable optical disk is possible.

A DVD-VI which is a read-only optical disk
DEO protects the copyright of AV data as follows. As shown in FIG. 7, the structure of a DVD-Video disk is roughly divided into a lead-in area 2 in which disc management information is recorded and a data area 1 in which AV data is recorded. I have. AV data scrambled by predetermined key data different for each AV data is pre-pit-recorded in the data area 1, and the control data block 3 stored in a predetermined address area in the lead-in area 2 stores the scramble key data in advance. Pre-pit recorded. DVD-
The VIDEO playback device reads the scramble key data written in the control data block 3 in the lead-in area at the time of startup, and if it is found that the activated disk has the scrambled AV data, the corresponding AV When data is reproduced, the AV data is descrambled using the scramble key and then reproduced. When there is a transfer request of AV data from the digital device to the DVD reproducing apparatus, the copyright of the AV data can be protected by rejecting the transfer of the AV data after descrambling. Since the AV data before descrambling, that is, the scrambled AV data cannot be restored to the original AV data unless the scramble is broken, it can be read using a DVD-ROM playback device or the like.

Although the copyright of AV data can be protected by the above copyright protection method, illegal digital copying is inevitable in a recordable optical disk in which all contents of a read-only optical disk can be written in the same format. Therefore, it is necessary to design the recordable optical disc so that all areas of the read-only optical disc cannot be written in the same format. FIG. 8 shows a first example of a conventional recordable optical disk, wherein 1 is a data area, 2 is a lead-in area, 3 is a control data block, and 5 is a pre-pit recording area. The biggest problem with digital copying is the scramble key,
-When reproducing a recordable optical disk in a VIDEO reproducing apparatus, if a scramble key can be read out in the same manner as a read-only optical disk, descrambling of scrambled AV data becomes possible, and illegal digital copying is established. Therefore, as shown in FIG. 8, for the control data block 3 which is a data area in which the scramble key data exists, an invalid scramble key is set in a portion where the scramble key data is contained, and the pre-pit is previously set. It is possible to record. However, the control data block is a block storing information about the disc, and information other than the scramble key is also written. For example, in a DVD, the start address and the end address of the data area are also stored in the control data block. However, in a recordable optical disk, since the capacity of the data area changes depending on the content written to the data area, the end address of the data area needs to be rewritten at the time of data writing. If the entire control data block 3 is pre-recorded in pre-pits, it is not possible to rewrite a portion of the control data block that requires rewriting as described in the example. Therefore, as shown in FIG. 9, a method is conceivable in which at least the scramble key portion in the control data block 3 is recorded in advance with pre-pits, and the other portions can be rewritten. here,
(FIG. 9) is a second example of a conventional recordable optical disc, wherein 1 is a data area, 2 is a lead-in area, 3 is a control data block, 4 is a writable area,
Reference numeral 5 denotes a pre-pit recording area.

A method for making a part of the control data block rewritable will be described below. FIG. 10 shows an ECC block structure of a DVD. (FIG. 10)
1 indicates an information word area, and 102 indicates a parity area for the information word area 101. B (0,0) to B (207,18
An error correction code is formed by 37856 bytes of data shown in 1). In DVD, to obtain a strong burst error correction capability, GF (2
56) on the Reed-Solomon product code (minimum intersymbol distance d
, D = 11 for the inner code and d = 17 for the outer code) constitute an error correction code. Such a unit of the error correction code is called an ECC block. When actually recording the data on the disk, as shown in FIG. 11, every 12 lines of the inner code corresponding to the information word portion of the outer code, one line of the inner code corresponding to the parity word of the outer code is interleaved and recorded as one sector. I have. Here (FIG. 11) is a diagram showing outer code interleaving at the time of recording, where 111 is an information word area and 112 is a parity area. FIG. 12 shows the structure of a control data block of a DVD. 1 is a data area, 2 is a lead-in area, 3 is a control data block, 6 is a data start address, 7 is a data end address, 8 is physical format information, 9 is disc manufacturer information, and 10 is content distributor information. . As a breakdown of the 16 sectors that make up the control data block,
The first sector is physical format information 8, the second sector is disk manufacturer information 9, and the third to sixteenth sectors are content distributor information 10 including a scramble key. Here, the information from the second sector to the sixteenth sector can be determined at the time of manufacturing the disk, and therefore can be recorded in pre-pits in advance except for the outer code parity part. Here, for the data from the second sector to the sixteenth sector, for example, all zeros are written in order to invalidate the scramble key, and the following description will be continued. When writing data in the data area, the physical format information of the control data block is written.
As shown in 3), the first sector has physical format information including the end address of the data area, and the second sector has 16
Outer code parity generation is performed by setting all zeros to the first sector, then inner code generation of the first sector and outer code parity part is performed, and then the outer code interleaved in the first sector and each sector is converted to (FIG. 14). It is recorded sequentially as shown. The scramble key is invalid and the data area end address of the physical format information is correctly recorded in the recordable optical disc thus completed. Here, FIG. 13 is a diagram showing a conventional error correction encoding method, where 131 is physical format information, 132 is zero data, and 133 is a parity to be generated. In addition, FIG.
4) is a conventional control data block writing method, 141 is data that has been recorded in advance in pre-pits,
142 is data to be recorded later.

[0008]

However, in this method, there is a risk that a read-only optical disk is illegally digitally copied to a recordable optical disk as shown below. (Figure 1
5) represents an error correction encoding method for illegally reproducing a scramble key on a conventional optical disc,
151 is the scramble key data read from the copy source disk, 152 is the outer code parity generated assuming that the scramble key data is written in the scramble key information section, and 153 is other data. As shown in FIG. 15, the first sector is filled with physical format information to be written, and other than the scramble key data portion from the second sector to the 16th sector is filled with zero, and the scramble key data portion is reproduced to be copied. EC filled with scramble key data read from a dedicated disc in advance
A C block is created, and ECC encoding of an inner code and an outer code is performed. In this case, since the outer code is a code generated on the assumption that the scramble key exists, (FIG. 1
When the state after the recording is viewed as the outer code as in 4), even if the state is completely read without error, the code having errors already inserted by the number of rows (the number of inner codes) of the scramble key data is the same as the code. Can be considered. That is, correction is possible if the number of error symbols is half or less (8 in the case of DVD) of (minimum inter-code distance of outer code -1). Furthermore, overwriting some data in the scramble key data part later,
If the original code data formed by the prepits is destroyed so that the inner code uncorrectable flag, that is, the erasure flag is set, (the number of erasures + the number of normal errors × 2) becomes (the minimum inter-code distance of outer code−1 ) Corrections are possible as long as: In the case of DVD, if all the correction capabilities of the outer code are passed to erasure correction, the maximum is (minimum inter-code distance of outer code -1).
In other words, correction of 16 symbols is possible, and even if the scramble key data occupies an area for one sector (about 2 kilobytes), it can be completely corrected because it is only 13 symbols in terms of the outer code. (FIG. 16) shows a method of illegally reproducing a scramble key in a conventional optical disk. A scramble key information portion 161 is destroyed by overwriting a prepit recording area, and a scramble key information portion 162 is written with scramble key data in a scramble key information portion. The outer code parity 163 generated assuming that the data is present indicates other data. As shown in FIG. 16, if one sector of a scramble key data storage sector in which zero data is previously recorded in pre-pits is overwritten and destroyed, and if the inner code of the region becomes uncorrectable, the data is lost. By using the correction, it is possible to perform an error correction that restores the scramble key data. By such an error correction operation, a control data block completely identical to the read-only disc originally containing the scramble key data can be obtained from the illegally copied recordable disc.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a recordable optical disk and a recording method for making digital copy from a read-only optical disk to a recordable optical disk impossible.

[0010]

According to the present invention, there is provided a recordable optical disk in which a first area in which data is recorded and fixed data including invalid scramble key data for disabling descrambling of data are erased in advance. A second area having a control information recording area consisting of two areas, a permanent recording area permanently recorded in an impossible form and a writable area,
In the permanent recording area, an error enough to make error correction impossible is inserted in advance into a part of an inner code belonging to an area where no scramble key data exists.

In the recording method for a recordable optical disk according to the present invention, when recording in the first area, an error correcting code encoding step for generating normal inner code parity and outer code parity for data to be written is provided. Comprises an entire recording step of recording the entire generated error correction code on the optical disc, and when recording the control information recording area,
The method includes an inner code encoding step of generating an inner code parity for the inner code of the writable area, and a partial recording step of recording the generated inner code of the writable area in the writable area of the optical disc.

In the recording method for a recordable optical disk according to the present invention, when recording in the first area, an error correction code encoding step for generating normal inner code parity and outer code parity for data to be written is provided. Comprises an entire recording step of recording the entire generated error correction code on the optical disc, and when recording the control information recording area,
An inner code encoding step of generating an inner code parity for the inner code of the writable area, and an inner code of a permanent recording area and an inner code of a part of the writable area in which an error is inserted in advance so that the error cannot be corrected. An erasure flag setting step of setting an erasure flag of the parity number of the total outer code at the position; and an outer code encoding step of performing erasure correction of the outer code by regarding the inner code position where the erasure flag is raised as an erasure position. And recording the inner code of the writable area in the writable area of the optical disk.

In the recording method for a recordable optical disk according to the present invention, when recording in the first area, an error correction code encoding step for generating normal inner code parity and outer code parity for data to be written is provided. Comprises an entire recording step of recording the entire generated error correction code on the optical disc, and when recording the control information recording area,
An inner code encoding step for generating an inner code parity for an inner code of the writable area, an outer code encoding step for generating an outer code parity, and recording the generated inner code of the writable area in a writable area of the optical disc. This is provided with a partial recording step.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a recordable optical disk of the present invention. 1 is the lead-in area,
2 is a data area, 3 is a control data block,
4 is a writable area and 5 is a pre-pit recording area. The control data block 3 includes a writable area 4 and a pre-pit recording area 5.

The data structure of the control data block 3 of the recordable optical disk according to the present invention is the same as that shown in FIG. 12 and is compatible with a read-only optical disk. The difference from the conventional technique is that not all the control data blocks 3 are pre-pit-recorded, so that physical format information that needs to be rewritten at the time of writing data, such as the end address of a data area, can be correctly handled. While making the pre-pit recording area and the rest a writable area,
This is to make it impossible to copy the scramble key data and to prevent digital copying of the disk containing the scrambled AV data.

FIG. 2 shows an error correction code configuration of a control data block of the optical disc in this embodiment. In FIG. 2, reference numeral 21 denotes a normal inner code of the pre-pit area, 22 denotes an inner code of the pre-pit area in which an error has been inserted in advance, and 23 denotes an inner code of a writable area. In this embodiment, the number of parities of the outer code is 16 (the minimum inter-code distance is 17), the code length of the outer code is 208, and one sector corresponds to 13 lines of the inner code like DVD, and the last inner code of one sector. Are described as interleaving the inner code of the outer code parity area. FIG. 2 shows the ECC block structure after the outer code interleaving, and the inner codes (16 codes in total) of the outer code parity area all belong to the pre-pit area, and errors that cannot be corrected in advance are removed. Inserted. Also, the inner code in the other pre-pit area does not insert an error, and the inner code is normally encoded. In the writable area, an inner code is generated for the data content to be written, and then written to the optical disc. As described above, when reproducing the control data block of the recordable optical disc in the present embodiment, instead of generating the parity of the outer code, an error is inserted in the inner code of the outer code parity part in advance so that the error cannot be corrected. Therefore, the error correction capability of the outer code can be completely invalidated. This will be described in detail.

When reproducing the control data block of the recordable optical disk in this embodiment, description will be made on the assumption that error correction of an outer code is performed next to an inner code. First, as the first step, error correction of the inner code is performed. At this time, if no burst error has occurred due to scratches,
Error correction is performed for all inner codes in which no error is inserted in advance that makes error correction impossible. In the inner code correction step, an erasure flag is set at a code position where correction is impossible so that erasure correction can be performed by the next outer code.
That is, an erasure flag is set at the position of the inner code (16 in total) into which an error enough to make error correction impossible is inserted in advance. In the next step, outer code error correction is performed. If the number of erasure flags is within the erasure correction limit, erasure correction is performed. The erasure correction limit is (minimum inter-code distance -1)
In the case of the outer code, it is 16. Therefore, error correction is performed at all positions where the erasure flag is set in the previous inner code error correction step. Since the correction of the erasure correction limit,
If there is an error in a place other than the disappearance position, it cannot be corrected. Therefore, it is unlikely that the scramble key data portion is illegally reproduced, as was the problem in the conventional example.

Next, an error detection code in the DVD will be described. FIG. 3 shows the recording data structure of one DVD sector. In FIG. 3, reference numeral 31 denotes user data and the like, reference numeral 32 denotes an error detection code parity, reference numeral 33 denotes an error correction code parity, and reference numeral 34 denotes an error detection code detection section. In the DVD, an error detection code (EDC) is encoded in addition to the error correction code, and even if an error correction by the error correction code occurs, a mechanism for detecting the error correction is provided. In the DVD, an error correction check is performed by an error detection code after error correction. However, the position of the inner code in the pre-pit area in which an error is inserted in such a way that the error cannot be corrected is located in the error detection code detection section 34. Since the inner code is corrected to an unexpected value by the erasure correction of the outer code, an error is detected by the error detection code. That is, the control data block cannot be normally reproduced. If the error detection code is provided separately from the error correction code as in the case of DVD, the position of the inner code in which an error that makes error correction impossible in advance is inserted in the pre-pit area is the detection interval of the error detection code. By arranging them so as to avoid them, it is possible to solve the problem that an error is detected by an error detection code.

Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a flow chart of a method for writing data on a recordable optical disk according to the present invention. In the optical disc recording method according to the present embodiment, first, as shown in S5-1,
It is determined whether the writing location is a control data block. If the block is not a control data block, error correction code encoding of an inner code and an outer code is performed as shown in S5-4, and then recording to the recording target block is performed as shown in S5-5. This is a normal data recording flow. Next, an operation in the case where it is determined in S5-1 that writing to the control data block is performed will be described. In that case, the inner code encoding of the writable area is first performed as shown in S5-2. Next, without performing outer code encoding, recording is performed in a writable area in the control data block as shown in S5-3. As described above, when recording to the control data block, the outer code is not encoded, and since the 16 inner codes that cannot be corrected are already recorded in the pre-pit area at the time of manufacturing the disc, the second code is used. 1
As described in the embodiment, the correction capability of the outer code can be completely invalidated. Therefore, it is unlikely that the scramble key data portion is illegally reproduced, as was the problem in the conventional example.

Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. (FIG. 6) is a flowchart of the recording method of the recording type optical disc of the present invention. In the optical disk recording method according to the present embodiment, first, as shown in S6-1,
It is determined whether the writing location is a control data block. If it is not a write to the control data block, S6-6, S6-
Proceeding to the process of 7, the recording ends. Next, an operation when it is determined that writing to the control data block is performed will be described. First, inner code encoding of the writable area is performed as shown in S6-2. Next, as shown in S6-3, an erasure flag is set for the inner code of the outer code parity area in the writable area and the inner code with the error inserted in the pre-pit area. Then, the erasure correction of the outer code is performed as shown in S6-4. Here, a description will be given assuming that the control block to be written in the present embodiment has a structure as shown in FIG. In FIG. 4, reference numeral 41 denotes an inner code of an outer code parity position (in a writable area), and reference numeral 42 denotes an inner code of an outer code parity position (in a pre-pit recording area). In this embodiment, the inner code 41 of the outer code parity position in the writable area and the inner code 4 of the outer code parity position in the pre-pit recording area are used.
The outer code encoding is performed by setting an erasure flag to 2. Since there are two inner codes 41 and fourteen inner codes 42, a total of 16 erasure flags are set. As described above, in the case of a DVD, the outer code is encoded by setting the erasure flag only for the inner code of the outer code parity area and avoiding the error detection code detection section in the case of DVD. This is because detection is performed.

When the present invention is applied to an optical disk having no error detection code, the inner code for setting the erasure flag in the writable area need not be the inner code at the outer code parity position. When the inner code at the outer code parity position is fixed and the other inner codes are made variable to reversely generate an outer code that matches the parity, erasure correction is effective as described in this embodiment.

However, when the erasure flag is set for the inner code at the outer code parity position as described in the present embodiment, the result is equivalent to obtaining the normal outer code parity. Instead, ordinary outer code encoding may be performed.

After the outer code has been generated in this manner, S6
As shown in -5, recording is performed in a writable area in the control data block.

As described above, when writing to the control data block is performed as in the present embodiment, since the inner code used as the outer code parity in the writable area is eight, correction of up to four symbols in the outer code is not possible. It is possible. As described above, when the method of writing data on the optical disk described in this embodiment is used, the error correction capability of the outer code can be limited. If this feature is applied to the problem of unauthorized reproduction of scramble key data described in the conventional example, it can be considered as follows. When the erasure flag is forcibly set at the time of reproduction by overwriting the scramble key data portion and destroying the recorded data as in the method described in the conventional example, this corresponds to eight inner codes. There is a possibility that the scramble key data corresponding to a part, that is, two thirds of the sector data, is illegally read. In a scramble system having a long scramble key that does not break the scramble even if the scramble key data portion corresponding to the eight inner codes is broken, the outer code is used to record 4 symbols as the outer code by the optical disk recording method shown in this embodiment. It can be said that there is no problem even if the correction ability is provided. Similarly, even if the scrambling key included in the N inner codes (0 ≦ N ≦ 15) is broken, if the scrambling system does not fail, the number of inner codes in which errors are inserted in advance in pre-pits is determined. To (16−N), the outer code can have (N / 2) symbol correction capability. In this way, even if a small amount of burst error is included, the control data block can be reproduced.

[0025]

As described above, according to the present invention, the first area in which the scrambled data is recorded and the fixed data including invalid scramble key data for disabling the descrambling of the data are not erased beforehand. A second area having a control information recording area consisting of two areas, a permanent recording area permanently recorded in a possible form and a writable area, and a permanent recording area belonging to an area where no scramble key data exists in the permanent recording area. The error correction capability of the outer code only in the control information recording area can be limited by inserting an error that cannot be corrected in advance into a part of the code, so that the scramble key data in the control information recording area is tampered with illegally. As a result, it is possible to realize a recordable optical disk in which digital copying from a read-only optical disk is impossible.

Further, a first area in which the scrambled data is recorded, and a permanent data in which fixed data including invalid scramble key data for disabling the descrambling of the data are permanently recorded in advance in a non-erasable manner. An optical disc writing method comprising: a second area having a control information recording area including two areas of a recording area and a writable area, and performing error correction coding with a product code of an inner code and an outer code and recording. When recording in the first area, an error correction code encoding step for generating normal inner code parity and outer code parity for data to be written, and an entire recording for recording the entirety of the generated error correction code on an optical disc. When recording in the control information recording area, an inner code parity with respect to the inner code of the writable area is provided. Is provided, and a partial recording step of recording the generated inner code of the writable area in the writable area of the optical disc is provided, whereby the error correction capability of the outer code only in the control information recording area can be limited. Therefore, it is possible to realize a recording method for a recordable optical disk in which the scramble key data in the control information recording area cannot be tampered with illegally.

Similarly, a first area in which scrambled data is recorded and fixed data including invalid scramble key data for disabling data descrambling are permanently recorded in a form that cannot be erased in advance. A second area having a control information recording area composed of two areas, a permanent recording area and a writable area, and performing error correction coding with a product code of an inner code and an outer code and recording the same. When recording in the first area, an error correction code encoding step for generating normal inner code parity and outer code parity for data to be written, and recording the entire generated error correction code on the optical disc. When recording in the control information recording area, an inner code is used for the inner code of the writable area. An inner code encoding step of generating a parity, and a parity number of a total outer code at a position of an inner code of the permanent recording area and an inner code of a part of the writable area, in which an error that cannot be corrected beforehand is inserted. An erasure flag setting step of setting an erasure flag of an inner code, an outer code encoding step of performing erasure correction of an outer code by regarding an inner code position where the erasure flag is set as an erasure position, and an inner code of the generated writable area on an optical disc. By providing a partial recording step of recording in the writable area, the error correction capability of the outer code only in the control information recording area can be limited, so that the scramble key data in the control information recording area cannot be tampered with. A recording method can be realized.

Similarly, a first area in which scrambled data is recorded and fixed data including invalid scramble key data for disabling descrambling of data are permanently recorded in a form that cannot be erased in advance. A second area having a control information recording area composed of two areas, a permanent recording area and a writable area, and performing error correction coding with a product code of an inner code and an outer code and recording the same. When recording in the first area, an error correction code encoding step for generating normal inner code parity and outer code parity for data to be written, and recording the entire generated error correction code on the optical disc. When recording in the control information recording area, an inner code is used for the inner code of the writable area. By providing an inner code encoding step for generating parity, an outer code encoding step for generating outer code parity, and a partial recording step of recording the generated inner code of the writable area in the writable area of the optical disc, Since the error correction capability of the outer code can be limited only in the information recording area, it is possible to realize a recording type optical disc recording method in which the scramble key data in the control information recording area cannot be tampered with illegally.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a recording-type optical disc according to a first embodiment.

FIG. 2 is an ECC block configuration diagram of a control data block in the first embodiment.

FIG. 3 is a configuration diagram of recording data of one sector of a DVD.

FIG. 4 is an ECC block configuration diagram of a control data block in a third embodiment.

FIG. 5 is a flowchart showing a recording method of an optical disc in a second embodiment.

FIG. 6 is a flowchart showing a recording method of an optical disc in a third embodiment.

FIG. 7 is a structural diagram of a read-only optical disk.

FIG. 8 shows a first example of a conventional recordable optical disk.

FIG. 9 shows a second example of a conventional recordable optical disk.

FIG. 10 is a configuration diagram of an error correction code unit.

FIG. 11 is a diagram illustrating an outer code interleaving method during recording.

FIG. 12 is a structural diagram of a control data block of a read-only optical disk (DVD).

FIG. 13 shows a conventional error correction encoding method.

FIG. 14 shows a conventional control data block writing method.

FIG. 15 shows an error correction encoding method for illegally reproducing a scramble key on a conventional optical disk.

FIG. 16 shows a method of illegally reproducing a scramble key on a conventional optical disk.

[Explanation of symbols]

Reference Signs List 1 data area 2 lead-in area 3 control data block 4 writable area 5 pre-pit recording area 6 data area start address 7 data area end address 8, 131 physical format information 9 disc manufacturer information 10 content distributor information 11 scramble key 21, 41 Normal inner code of pre-pit area 22, 42 Inner code of pre-pit area with error inserted beforehand 23, 43 Inner code of writable area 31 User data etc. 32 Error detection code (EDC) parity 33 Error detection code (inner code, Outer code) Parity 34 Error detection code detection section 101, 111 Information word area (including inner code) 102, 112 Parity area 132 Zero data 133 Parity to be generated 141 Data previously recorded in pre-pits 142 Data to be recorded later 151 Scramble key data read from copy source disk 152, 162 Invalid outer code parity 153, 163 generated assuming that scramble key data is written in scramble key information section 153, 163 Other data 161 Prepit Scramble key information section destroyed by overwriting the recording area

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D044 BC04 CC04 DE49 DE50 DE68 EF05 FG18 GK17 HL08 5D090 AA01 BB02 BB04 CC01 CC04 CC14 DD03 DD05 FF09 FF29 FF42 FF49 GG16 GG29 GG32 GG33 GG34 HH01

Claims (17)

[Claims] An optical disc for digitally recording data by performing error correction coding on data with a product code of an inner code and an outer code, and comprising:
Fixed data including invalid scramble key data is permanently recorded in a non-erasable form in advance in order to disable recording of a first area where data is recorded and scramble key information for descrambling the data. And a second area having a control information recording area consisting of two areas, a permanent recording area and a writable area. The number of symbols of invalid scramble key data included in the outer code is n.
Wherein the number of parity symbols is n or more, and the number of symbols that can be used to write arbitrary data substantially unused in the writable area is less than n. 2. The recording type optical disk according to claim 1, wherein an error that makes error correction impossible is inserted in advance into a part of the inner code belonging to an area where no scramble key data exists in the permanent recording area. 3. The recordable optical disk according to claim 1, wherein writing to the optical disk is a write-once. 4. An error correction code used is GF (256).
2. The recordable optical disk according to claim 1, wherein said optical disk is a Reed-Solomon code. 5. The recordable optical disk according to claim 2, wherein the number of inner codes for inserting an error for which error correction cannot be performed in advance is not less than 1 and not more than the number of parity symbols of an outer code. 6. The recordable optical disk according to claim 5, wherein the number of parity symbols of the outer code is 16. 7. The recordable optical disk according to claim 6, wherein the number of inner codes for inserting an error that cannot be corrected in advance is eight. 8. The position of an inner code for inserting an error which makes error correction impossible in the permanent recording area in advance is set so as to avoid a check section of an error detection code provided separately from the error correction code. The recordable optical disk according to claim 2, wherein: 9. The recordable optical disk according to claim 2, wherein the position of the inner code in which an error which cannot be corrected in advance is inserted in the permanent recording area is a parity position of the outer code. 10. A product code according to a DVD format,
For the outer code, the number of parity symbols in the permanent recording area is (1).
7. The recordable optical disc according to claim 1, wherein the content is not less than 7-n). 11. The recordable optical disk according to claim 5, wherein the product code conforms to a DVD format. 12. The recordable optical disc according to claim 9, wherein the product code conforms to a DVD format. 13. A fixed area including invalid scramble key data cannot be erased in advance in order to disable recording of a first area where data is recorded and scramble key information for descrambling the data. And a second area having a control information recording area consisting of two areas, a permanent recording area which is permanently recorded in a fixed form, and a writable area. An optical disc writing method, wherein when recording in the first area, an error correction code encoding step for generating normal inner code parity and outer code parity for data to be written; It comprises an entire recording step of recording the entirety on the optical disc. Recording optical disk, comprising: an inner code encoding step for generating an inner code parity for a signal; and a partial recording step of recording the generated inner code of the writable area in the writable area of the optical disk. Recording method. 14. A fixed area including invalid scramble key data cannot be erased beforehand in order to disable recording of a first area where data is recorded and scramble key information for descrambling the data. And a second area having a control information recording area consisting of two areas, a permanent recording area which is permanently recorded in a fixed form, and a writable area. An optical disc writing method, wherein when recording in the first area, an error correction code encoding step for generating normal inner code parity and outer code parity for data to be written; It comprises an entire recording step of recording the entirety on the optical disc. At the position of the inner code of the permanent recording area and the part of the inner code of the writable area, in which an error that cannot be corrected beforehand is inserted. An erasure flag setting step for setting an erasure flag of the total outer code parity number; an outer code encoding step for performing erasure correction of the outer code by regarding the inner code position where the erasure flag is raised as an erasure position; A recording method for a recordable optical disc, comprising a partial recording step of recording an inner code of an area in the writable area of the optical disc. 15. The position of a part of inner codes for setting an erasure flag in a writable area is set so as to avoid a check section of an error detection code provided separately from an error correction code. The recording method of the recordable optical disk according to the above. 16. The recording method for a recordable optical disk according to claim 15, wherein a position of a part of the inner code for setting the erasure flag in the writable area is a parity position of an outer code. 17. A fixed area including invalid scramble key data cannot be erased in advance to disable recording of a first area in which data is recorded and scramble key information for descrambling the data. And a second area having a control information recording area consisting of two areas, a permanent recording area which is permanently recorded in a fixed form, and a writable area. An optical disc writing method, wherein when recording in the first area, an error correction code encoding step for generating normal inner code parity and outer code parity for data to be written; It comprises an entire recording step of recording the entirety on the optical disc. Inner code encoding step for generating an inner code parity for a signal, outer code encoding step for generating an outer code parity, and partial recording step of recording the generated inner code of the writable area in the writable area of the optical disc. A recording method for a recordable optical disk, comprising: